The three-week, 2,287-mile Tour de France, Europe's premier bicycle race, is one of the world's great tests of human endurance. Every summer more than 10 million fans line the roadsides--and millions more tune in on TV--to watch the riders sprint, climb and sweat their way through every variety of French landscape. The race finishes on the Champs Elysees in Paris, where the winner gets a hero's welcome.
In a sense, Lance Armstrong started the race a hero. In 1996 the Texas-born cyclist was found to be suffering from testicular cancer that had spread to his brain and lungs. The prognosis could...